It is generally known to form optical fibers into a panel or the like and make the panel luminous in one or more selected areas by altering the total internal reflection character of the optical fibers in such areas. Illumination in these areas is caused by allowing light transmitted into the optical fibers from a remote light source to emerge from the optical fibers in the selected areas.
Normally the light entering one end of an optical fiber passes out the other end thereof after a certain amount of loss takes place. However, if the surface of the optical fiber is disrupted as by scratching or otherwise deformed as by bending the optical fiber at a plurality of discrete locations along its length such that the angle of bend approximately exceeds the angle of-internal reflection light will be emitted at these locations.
A conventional optical fiber light emitting panel 100 is shown in FIG. 1. The panel is formed of a plurality of cladded optical fibers arranged in an abutting side-by-side essentially parallel relationship and extending over a predetermined area 103. The distal ends 105 of the optical fibers are typically cut and polished. The proximal ends 107 of the optical fibers are bundled together with a band 109 such that a single light source may be used to illuminate the panel. The diameter 111 of the bundle increases with the number and diameter of the individual optical fibers. The gradual gathering of the optical fibers from their essentially parallel relationship to a bundle produces a fan-in arrangement 113. Typically, the length of the fan-in arrangement 115 is one and one-half times the distance across the essentially parallel optical fibers 117. The optical fibers may optionally be bundled into a cable 119 for routing to a remote location.
A problem with the conventionally formed optical fiber light emitting panel 100 is the space consumed by the fan-in arrangement 115. Although optical fiber light emitting panels provide certain advantages over other lighting apparatus, some lighting applications, such as portable electronics, simply cannot use the conventional optical light emitting panel because of the amount of space available for the fan-in arrangement.
Therefore, there is a need for an improved optical fiber light emitting panel providing essentially the same advantages as the conventional optical fiber light emitting panel but consuming less space.